<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>并集选择器</title>
    <!-- 并集选择器，指选中多种选择器 -->
    <style>
        h1,p,h2 {
            color: aqua;
        }
    </style>
</head>
<body>
    <h1>这是h1</h1>
    <p>这个是p标签</p>
    <span>这是span</span>
    <h2>这是h2</h2>
</body>
</html>